This paper introduces the latest progress and research results of robotic unordered picking technology, and provides research ideas and technical support for robot automation application in complex scenarios. It discusses three key technical tasks in the robot unordered picking process, which including detection and recognition of cluttered objects, spatial pose estimation of objects, grasping strategy of unordered picking. Analyzes and summarizes the methods involved in each task. The main challenges of robotic unordered picking technology today are dealing with visual perception, pose estimation and grasping strategy of cluttered and stacked objects in complex environments. Specific picking systems should be designed considering the actual scenario environment and combined with the task requirements in order to achieve the goal of replacing human labor by robots as much as possible.